Histopathologic examination of all 3 biopsy specimens revealed diffuse dermal infiltrates (Figure 2) composed of monotonous, medium-sized, round lymphocytes (Figure 3) that were strongly positive for CD20. Immunhistochemical analysis also revealed a background infiltrate of CD3-positive T lymphocytes. A bone marrow biopsy specimen, which was obtained for evaluation of the patient's thrombocytopenia and anemia, revealed small atypical lymphoid cells replacing approximately 90% of the cellular component of the bone marrow. Flow cytometric analysis of the bone marrow demonstrated κ-restricted monoclonal B cells that were positive for CD19, CD20, CD23, and CD5. Fluorescence in situ hybridization analysis showed a 13q14.3 deletion in 80% of the bone marrow cells. These findings were consistent with B-CLL with cutaneous involvement.